Why did some WW2 planes have hoops around them?

[Sedalia Dave]

 

[Subdeacon Joe]

We had the Catalina 

 

And then there is the VB-138

 

The thread had the comment: "You can tell the 138 is a Richard Vogt design because you can bolt a giant electric hula hoop to it and it doesn't make it look any weirder than it did before"

[J.D. Daily]

My educated guess is the hoops were metal detector coils that operated in the VLF radio spectrum.  May have been tried on marine patrol aircraft before Tail End Charlie X band radar was deployed to detect ships & surfaced submarines at night.

[Badger Mountain Charlie SASS #43172]

The Martians did it.

 

Or perhaps ir was the Klingons. 

[Dubious Don #56333]

Mine removal. The magnetic field set off the mine when the aircraft flew over'em.

[Linn Keller, SASS 27332, BOLD 103]

My first thought was a loop antenna, but magnetic field anti-mine ops makes more sense.

[Texas Lizard]

My first thought was keep stupid people from walking into moving props...Hey what do I know...I only worked on B-52...

 

Texas Lizard

[Pat Riot]

Airborne mine sweepers, whoda thunk it? Thanks Dave.

 

When  first saw this I thought it might be some type of antenna for picking up weak radio signals.